One type of controller enclosures (CEs) provided to storage apparatuses is known, wherein midplanes (MPs) are provided in the central part of housings and multiple modules can be mounted to and unmounted from the MPs, from the front and/or rear of the housings.
Additionally, techniques to provide such CEs with redundancy by duplicating modules which are inserted into or are removed from the MPs have been known. In such a configuration, when one of the duplicated modules fails, a hot replacement of the failed module can be carried out, without stopping the operation of the storage apparatus.
Patent Document 1: Japanese National Publication of International Patent Application No. 2002-516493
Patent Document 2: Japanese Laid-open Patent Publication No. 2009-217519
Patent Document 3: Japanese Laid-open Patent Publication No. 2010-49716
Patent Document 4: Japanese Laid-open Patent Publication No. 2006-155392
In storage apparatuses as described above, however, since an MP is not duplicated, in the case of a failure of the MP, the operation by the storage apparatus is stopped for making a replacement of MPs.